Field
Implementations described herein generally relate to etheramine mixtures formed from a mixture of two or more multifunctional alcohol initiators, processes for the etheramine mixtures production, and its use as a curing agent or as a raw material in the synthesis of polymers.
Description of the Related Art
Polyoxyalkylene amines, or “polyetheramines” as they are sometimes called, are useful as curing agents in epoxy systems to improve flexibility, and to lengthen working time in the manufacture of fiber-reinforced composites. Polyetheramines are generally produced by the reaction of an alkylene oxide with an alcohol to form a polyoxyalkylene polyol and then the hydroxyl groups are subsequently converted to amine groups by reductive amination. For example U.S. Pat. No. 3,654,370 describes a process in which a polyoxyalkylene polyol is treated with ammonia and hydrogen in the presence of a nickel oxide, copper oxide and chromium oxide catalyst to form a mixture of polyether amines. U.S. Pat. No. 4,766,245 further describes a process in which high molecular weight polyoxyalkylene amines are produced by contacting high molecular weight polyoxyalkylene polyols with ammonia in the presence of hydrogen and a Raney nickel/aluminum catalyst. Additionally, U.S. Pat. No. 4,769,438 describes a process in which a propoxylated 1,4-butanediol is first aminated using a Raney nickel catalyst and then subsequently converted to an adduct by a reaction with a small amount of an epoxy resin. Finally, U.S. Pat. No. 7,550,550 describes a process for producing hindered polyetherdiamines and polyethertriamines by reductive amination of a variety of polyoxyalkylene polyols.
In some processes for producing polyetheramines, the alcohol precursors used for alkoxylation are typically liquids at room temperature or low melting point solid raw materials. Due to high energy consumption and requirement of more capital investment to add heat tracing capability, higher melting point raw materials are typically excluded from current processes. These high melting point raw materials, sometimes have unique features, such as, rigid backbone, high functionality etc.
Therefore, there is a need for improved processes for producing etheramine mixtures from two or more multifunctional alcohol initiators wherein at least one of the multifunctional initiators is a higher melting point alcohol.